Evidence exists which suggests that the cannabinoids can modulate the biosynthesis of prostaglandins both in vitro and in vivo. The objective of this project is to provide further data to help demonstrate whether some of the actions of cannabis are mediated by such a mechanism. Cell cultures as well as subcellular fractions from various tissues will be used as test systems. Labelled prostaglandin precursors will be administered and the products analyzed by chromatography and radioactive assay. By this method the effects of various natural and synthetic cannabinoids on biosynthesis can be measured.